Converter vessel with heat shield about its tap hole

ABSTRACT

A converter vessel rotatable about a horizontal axis and having a metal shell, internal insulation in the shell, an upper mouth, a tap hole in the upper part of the vessel below the mouth and a heat shield mounted on the vessel exterior surface in spaced relationship therefrom and covering the vessel metal shell area above and to the side of the tap hole to protect said shell area against severe heating during flow of material from the tap hole when the vessel is rotated. The heat shield can be an exposed substantially smooth surfaced metal plate supported in fixed position on the shell surface by brackets joined to, and extending outwardly from, the vessel surface.

United V States Patent Pieper et al.

[ 51 Aug. 8, 1972 [54] CONVERTER VESSEL WITH HEAT SHIELD ABOUT ITS TAP HOLE [72] Inventors: Charles Joseph Pieper, Downers Grove; Edmund Clarence Langmead, Jr., Glen Ellyn, both of III.

[73] Assignee: Chicago Bridge & Iron Company,

Oak Brook, Ill.

[22] Filed: Feb. 3, 1971 [21] Appl.No.: 112,127

[52] US. Cl ..266/35, 266/38 [51] Int. Cl. ..C2lb 7/14 [58] Field of Search ..164/337; 266/34 V, 38, 35,

[56] References Cited UNlTED STATES PATENTS 3,153,110 10/1964 Sherbum et al. ..266/38 Primary Examiner-Gerald A. Dost Attorney-Merriam, Marshall, Shapiro & Klose [57] ABSTRACT A converter vessel rotatable about a horizontal axis and having a metal shell, internal insulation in the shell, an upper mouth, a tap hole in the upper part of the vessel below the mouth and a heat shield mounted on the vessel exterior surface in spaced relationship therefrom and covering the vessel metal shell area above and to the side of the tap hole to protect said shell area against severe heating during flow of material from the tap hole when the vessel is rotated. The heat shield can be an exposed substantially smooth surfaced metal plate supported in fixed position on the shell surface by brackets joined to, and extending outwardly from, the vessel surface.

11 Claims, 7 Drawing Figures PATENTED F 8197? 3,682,460

sum 2 [1F 2 40 I7 24 P23 /r j A INVENTORS.

CHARLES JOSEPH PIEPER EDMUND CLARENCE LANGMEADJR ATTORNEYS.

CONVERTER VESSEL WITH HEAT SHIELD ABOUT ITS TAPE HOLE This invention relates to converter vessels used in metal production and refining. More particularly, this invention is concerned with improvements in rotatable converter vessels which protect the vessel shell around the tap hole against-excessive heat when material is poured therefrom.

Converter vessels are widely used in industrial processes, such as in steel manufacturing operations. They are generally made of a metal shell with an internal refractory lining. The top has a mouth for adding materials to the vessel for processing. The vessel is normally rotatable about a horizontal axis by means of trunnions on the vessel. When the vessel is rotated, processed material pours from a tap hole in the upper part of the vessel below the mouth. Vessels of this type are used for a number of purposes but especially in the basic oxygen steelmaking process. U.S. Pats. Nos. 3,191,921 and 3,441,262 disclose embodiments of such vessels.

When the hot material, normally molten metal, is poured to a teeming ladle from the tap hole of the converter vessel, heat radiating from the teeming ladle onto the converter shell above and to the sides of the tap hole causes that portion of the shell to become severely heated. This causes distortion of that portion of the converter vessel shell because expansion of the shell is limited to the heated area and confined around its perimeter by the cooler metal. The metal converter shell must yield to accommodate the expansion and in doing so it is distorted. The amount of distortion is relatively small for each individual exposure but becomes progressively worse during each of the tapping cycles per day. After a year or two, the vessel may become so badly distorted that it becomes necessary to replace a portion of the vessel shell at considerable expense and with loss of production.

It is not practical to attach insulating material to the outside of the vessel around the tap hole to protect the shell against the radiant heat during tapping. Although the vessel is lined inside with a refractory material, the shell temperature may exceed 800 F. in steel manufacturing because of heat from the molten metal inside of the vessel. Insulation placed directly against the exterior metal shell surface would prevent heat from escaping and thereby actually aids in raising the shell temperature. There is accordingly a need for a way to protect the converter vessel shell surrounding the tap hole against temperatures substantially different from shell temperatures outside of that portion of the shell. Either a cooler than normal or hotter than normal shell temperature around the tap hole will cause a problem.

According to the present invention there is provided improvements in converter vessels, of the general typedescribed above, which protect the vessel metal shell around the tap hole against heat induced distortion during tapping. In a broad embodiment of the invention, a heat shield is mounted on the vessel exterior surface in spaced relationship therefrom and covering the vessel metal shell area above and to the side of the tap hole to protect said shell area against severe heating during flow of material from the tap hole when the vessel is rotated.

The heat shield can have a number of forms. It can be an exposed substantially smooth surfaced metal plate supported in fixed position on the shell surface by brackets joined to, and extending outwardly from, the vessel surface. It can also be a heat shield having channels through which a fluid can be circulated to regulate the temperature of the heat shield. In addition, the heat shield can be a multiple layer sandwich or a honeycombed structure with insulation in the cells. Other structural forms can also be used, some of which will be described hereinafter.

The invention will now be described further in conjunction with the attached drawings in which:

FIG. 1 is a plan view of a converter vessel provided with a heat shield around the tap hole;

FIG. 2 is an enlarged plan view of the heat shield of FIG. 1;

FIG. 3 is a sectional view, taken along the line 3-3, of the heat shield of FIG. 2;

FIG. 4 is a side elevational view of a multiple layer heat shield having channels for circulating a heat regulating fluid therein;

FIG. 5 is a sectional view of the heat shield of FIG. 4 taken along the line 5-5;

FIG. 6 is a plan view, partly broken away and partly in section, of one section of a heat shield; and

FIG. 7 is a sectional view of theheat shield'of FIG. 6 taken along the line 7-7.

So far as is practical, the same number will be used to identify the same or similar parts or elements in the various figures comprising the drawings.

With reference to FIG. 1, the converter vessel 10 has an external metal shell 11 with an internal refractory lining (not shown). The top of vessel 10 has a circular opening or mouth 12 through which material is fed to the vessel for processing. On opposite sides of shell 11 is positioned a pair of trunnions 13 and 14 for rotating the vessel. Tap hole 15 communicates with the interior of the vessel and is located in the upper part of the vessel below the mouth. When the vessel is rotated on the trunnions, material in the vessel flows outwardly form the tap hole to a teeming ladle. The heat radiating from the hot material in the teeming ladle strikes heat shield 16 here shown in three sections 17, 18 and 19. Although the shield is shown in three sections, it can be made in one section and, in fact, section 18 can'comprise the entire heat shield by making it large enough to cover those parts of the converter vessel shell above and to the sides of the tap hole which would otherwise be subjected to the radiant heat.

Referring to FIGS. 2 and 3, in conjunction with FIG. 1, it will be seen that heat shield section 18 comprises a smooth surfaced metal plate supported on the vessel shell 11 by brackets 20. The brackets, while shown horizontally, could be positioned vertically, i.e., in line with the vessel axis. The bottom edge of brackets 20 conforms to the contour of the vessel shell surface and is provided with cut-out areas 21 to accommodate thermal expansion. The top of each bracket is straight so that it can abut in line contact with the bottom face of shield section 18. The brackets 20 can be welded to the vessel shell but bolted 23 to the heat shield metal plate. I-Ieat shield section 18 has a cut-out area 21 somewhat larger than the structure defining the tap hole so that it can be positioned to cover the vessel shell above and on both sides of the tap hole to thereby protect it against radiant heat.

Heat shield sections 17 and 19, on each side of central section 18 (FIGS. 2 and 3), are similar in construction to section 18 but do not have a tap hole accommodating cut-off area 21 as in section 18. Each of sections 17 and 19 have a flat plate 25 bolted 24 on brackets 22 which are similar to brackets 20. The height and width of heat shield sections 17 and 19 can be adjusted as required to protect the vessel shell against radiant heat when molten material is poured from the tap hole.

An important feature of the described heat shield, as well as the other embodiments described hereinafter, is that they are mounted on, but spaced away from, the vessel shell. There is thus a space between the vessel shell and the heat shield back which permits flow of air therethrough to moderate temperature differentials between the heat shield and the vessel shell. Heat is thereby permitted to escape from the shell without radiant heat exerting a significant effect on the shell.

Another embodiment of the invention is shown in FIGS. 4 and 5. The multiple layer heat shield 30 shown in these drawings has a bottom metal plate 29, a layer of insulation 31 thereon and a metal plate 32 on top of the insulation to thereby form a sandwich type heat shield. The heat shield is provided with channeled member 34 joined integrally to the rear surface of plate 29. Channeled member 34 can be formed of a series of angle shapes 37 placed side-by-side in abutting position and welded together and to plate 29 as shown in FIG. 5. Conduits 35 and 36 are used to circulate a fluid through channeled member 34. Brackets 42 are joined to the vessel shell 38 and bolts 39 join the heat shield to the brackets and hold the layers 29, 31 and 32 tightly together. Plate 40 is positioned on the top of the shield 30 sloped downwardly to prevent slag and dirt from accumulating on brackets 42 and thereafter falling off during tapping of the vessel and contaminating the product flowing from tap hole 41. Heat shield 30 has a cut-out area, not shown, similar to cut-out area 21 shown in FIG. 2 in order to position it closely around tap hole 41 (FIG. 4).

FIGS. 6 and 7 show a side section heat shield which can be used for sections 17 and 19 in FIG. 1. Plate 50 provides the heat protecting layer. Welded to the back of plate 50 is a series of angles 51 in side-by-side abutting staggered position to thereby define channels 52 through which a fluid can be circulated by conduits 54 and 55 to control the temperature of the heat shield. Plate 53 is placed over the ends of angled members 51 to insure against fluid leakage. The heat shield of this embodiment is mounted on a converter vessel shell in a manner similar to that described above in regard to FIGS. 1 to 3.

While we have shown and described certain embodiments of our invention it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In a converter vessel rotatable about a horizontal axis and having a metal shell, internal insulation in the shell, an upper mouth and a tap hole in the upper part of the vessel below the mouth, the improvement comfiiat shield mounted on the vessel exterior surface in spaced relationship therefrom and covering the vessel metal shell area above and to the side of the tap hole to protect said shell area against severe heating during flow of material from the tap hole when the vessel is rotated.

2. In a converter vessel according to claim 1 the heat shield comprising an exposed substantially smooth surfaced metal plate supported in fixed position on the shell surface by brackets joined to, and extending outwardly from, the vessel surface.

3. In a converter vessel according to claim 1, the heat shield having channels through which a fluid can be circulated to regulate the temperature of the heat shield.

4. In a converter vessel according to claim 1, the heat shield comprising at least two layers in face-to-face contact with each other, one layer being a metal plate and the other layer being a layer of heat refractory material.

5. In a converter vessel according to claim 1, the heat shield comprising at least three layers with a central layer of heat refractory material and a metal plate layer on each side thereof in face-to-face contact with the refractory layer.

6. In a converter vessel according to claim 5, the heat shield having a channeled member beneath the metal plate layer closest to the vessel surface through which a fluid can be circulated to regulate the temperature of the heat shield.

7. In a converter vessel according to claim 1, the heat shield having a pair of spaced apart metal surfaces with channels therebetween through which a fluid can be circulated to regulate the temperature of the heat shield.

8. In a converter vessel according to claim 1, the heat shield having a substantially flat outersurface.

9. In a converter vessel according to claim 1, the heat shield comprising three sections placed side-by-side with the central section portion at least partially surrounding the tap hole.

10. In a converter vessel according to claim 9, each of the three sections having channels through which a fluid can be circulated to regulate the temperature of each section.

11. In a converter vessel according to claim 1, the heat shield comprising a metal plate having lattice-like webs extending laterally from the surface thereof thereby defining cells, and a heat refractory material positioned in the cells. 

1. In a converter vessel rotatable about a horizontal axis and having a metal shell, internal insulation in the shell, an upper mouth and a tap hole in the upper part of the vessel below the mouth, the improvement comprising: a heat shield mounted on the vessel exterior surface in spaced relationship therefrom and covering the vessel metal shell area above and to the side of the tap hole to protect said shell area against severe heating during flow of material from the tap hole when the vessel is rotated.
 2. In a converter vessel according to claim 1, the heat shield comprising an exposed substantially smooth surfaced metal plate supported in fixed position on the shell surface by brackets joined to, and extending outwardly from, the vessel surface.
 3. In a converter vessel according to claim 1, the heat shield having channels through which a fluid can be circulated to regulate the temperature of the heat shield.
 4. In a converter vessel according to claim 1, the heat shield comprising at least two layers in face-to-face contact with each other, one layer being a metal plate and the other layer being a layer of heat refractory material.
 5. In a converter vessel according to claim 1, the heat shield comprising at least three layers with a central layer of heat refractory material and a metal plate layer on each side thereof in face-to-face contact with the refractory layer.
 6. In a converter vessel according to claim 5, the heat shield having a channeled member beneath the metal plate layer closest to the vessel surface through which a fluid can be circulated to regulate the temperature of the heat shield.
 7. In a converter vessel according to claim 1, the heat shield having a pair of spaced apart metal surfaces with channels therebetween through which a fluid can be circulated to regulate the temperature of the heat shield.
 8. In a converter vessel according to claim 1, the heat shield having a substantially flat outer surface.
 9. In a converter vessel according to claim 1, the heat shield comprising three sections placed side-by-side with the central section portion at least partially surrounding the tap hole.
 10. In a converter vessel according to claim 9, each of the three sections having channels through which a fluid can be circulated to regulate the temperature of each section.
 11. In a converter vessel according to claim 1, the heat shield comprising a metal plate having lattice-like webs extending laterally from the surface thereof thereby defining cells, and a heat refractory material positioned in the cells. 